The invention is in the field of extrinsic photoconductors having responses in the infrared spectrum. In particular, 3 to 5 and 8 to 14 microns are of interest to the military, and single-crystal silicon seed material is a specific material often used. Such photoconductors have heretofore been produced by various doping methods, such as vacuum evaporation, sublimation, electrodeposition, chemical vapor deposition, molecular beam deposition or sputtering. Those methods, because of various problems, are usually unable to produce high-quality single crystal growth with low compensation and high uniformity that extrinsic detector material must have. Some of the problems are:
(1) initiation of growth is severely hampered by residual oxygen or oxide formation in the growth system and/or in the silicon seed material, PA1 (2) control and reproducibility of layer growth is poor, PA1 (3) heavy doping levels are difficult to obtain, PA1 (4) the expenses of obtaining and maintaining high purity seed material are great.
My invention avoids all of these four problems.